1. Field of the Invention
The present general inventive concept relates to a method and apparatus to conceal an error of an audio signal, and more particularly, to a method and apparatus to conceal an error included in an audio signal by generating a parameter of a frame having an error, i.e., an error frame, in a predetermined way.
2. Description of the Related Art
An error such as a packet error or a bit error may occur during transmission of an audio signal over a wired or wireless network due to various network conditions. Without proper processing of the error, annoying distortion may occur, resulting in degradation of sound quality.
In order to conceal the error, a sender-based scheme that conceals the error in an encoder and a receiver-based scheme that conceals the error in a decoder have conventionally been used. The receiver-based scheme can be divided into a scheme using extrapolation and a scheme using interpolation.
The receiver-based scheme using the extrapolation conceals an error of a current frame using only parameter information of past frames having no error. Although this scheme has no additional delay because it uses only parameter information of past frames, it exhibits lower sound quality than when the receiver-based scheme using interpolation is used.
The receiver-based scheme using the interpolation conceals an error of the current frame using parameter information of past frames having no error and parameter information of future frames having no error. This scheme exhibits higher performance than the scheme using extrapolation, due to a large mount of information when there is no additional information. However, according to this scheme, a time delay occurs until a frame having no error is input.